#! /bin/bash -e
# $Id:$
# -----------------------------------------------------------------------------
# CppAD: C++ Algorithmic Differentiation: Copyright (C) 2003-15 Bradley M. Bell
#
# CppAD is distributed under multiple licenses. This distribution is under
# the terms of the
#                     Eclipse Public License Version 1.0.
#
# A copy of this license is included in the COPYING file of this distribution.
# Please visit http://www.coin-or.org/CppAD/ for information on other licenses.
# -----------------------------------------------------------------------------
#! /bin/bash -e
web_page='https://github.com/joaoleal/CppADCodeGen.git'
# -----------------------------------------------------------------------------
# bash function that echos and executes a command
echo_eval() {
	echo $*
	eval $*
}
# -----------------------------------------------------------------------------
cat << EOF
This is not a bug but rather a demonstration of using conditional expressions
with CppADCodeGen
	https://github.com/joaoleal/CppADCodeGen/
EOF
#
if [ ! -e build ]
then
	echo_eval mkdir -p build
fi
echo_eval cd build
cat << EOF > cppad_cg.cpp
# include <iosfwd>
# include <cppad/cg/cppadcg.hpp>
int main(void)
{	typedef CppAD::cg::CG<double> cg_double;
	typedef CppAD::AD<cg_double>  acg_double;

	// declare independent variables for f(x)
	size_t nx = 2;
	CppAD::vector<acg_double> ax(nx);
	ax[0] = 2.0;
	ax[1] = 3.0;
	CppAD::Independent(ax);

	// create dependent variables and values for f(x)
	// f(x) = x[0] / x[1] if (x[0] > 0 and x[1] >= x[0]) else 1.0
	size_t nz = 1;
	CppAD::vector<acg_double> az(nz);
	acg_double acg_zero   = acg_double(0.0);
	acg_double acg_one    =   acg_double(1.0);
	acg_double acg_temp_1 = CondExpGt(ax[1], ax[0], ax[0] / ax[1], acg_one);
	acg_double acg_temp_2 = CondExpGt(ax[0], acg_zero, acg_temp_1, acg_one);
	az[0] = acg_temp_2;

	// create AD function mapping independent to dependent variables
	CppAD::ADFun<cg_double> F(ax, az);

	// create the source code generator for function g(x)
	CppAD::cg::CodeHandler<double> G;

	// declare the independent variables for g(x)
	CppAD::vector<cg_double>   cg_x(nx);
	G.makeVariables(cg_x);

	// Compute the dependent variables and values for g(x)
	size_t ny = nz * nx;
	CppAD::vector<cg_double> cg_y(ny);
	cg_y = F.Jacobian(cg_x);

	// Mapping from variables in this program to variables in source_code
	// independent variable = x
	// dependent variable   = y
	// temporary variable   = v
	CppAD::cg::LanguageC<double> langC("double");
	CppAD::cg::LangCDefaultVariableNameGenerator<double> nameGen;

	// generate the source code
	std::ostringstream source_code;
	G.generateCode(source_code, langC, cg_y, nameGen);

	// string corresponding to source code
	std::string source_str = source_code.str();

	// C souce code corresponding to y = g(x)
	std::cout << source_str;

	return 0;
}
EOF
#
# Compile and run cppad_cg.cpp
echo_eval g++ \
	-g \
	-std=c++11 \
	-I$HOME/prefix/cppad_cg/include \
	-I../.. \
	cppad_cg.cpp -o cppad_cg
#
# Determine the maximum v index
v_max_index=`./cppad_cg | sed \
	-e '/^ *v\[[0-9]*\]/! d' \
	-e 's|^ *v\[\([0-9]*\)\].*|\1|'  | sort | tail -1`
#
#
# Wrap y = g(x) in C++ function and test it
cat << EOF > tst_cppad_cg.cpp
# include <cppad/cppad.hpp>
namespace {
	using CppAD::zdouble;
	typedef CppAD::vector<zdouble> zvector;
	//
	// f(x) = x[0] / x[1] if (x[0] > 0 and x[1] >= x[0]) else 1.0
	// g(x) = d/dx f(x)
	void g(const zvector& x, zvector& y)
	{	zvector v($v_max_index + 1);
EOF
./cppad_cg | sed -e 's|^ *|\t\t|' >> tst_cppad_cg.cpp
cat << EOF >> tst_cppad_cg.cpp
		return;
	}
}
int main(void)
{	// initialize flag
	bool   ok   = true;
	// numerical precision for tests
	zdouble eps = 10. * std::numeric_limits<double>::epsilon();
	// number of components in vectors
	size_t nx    = 2;
	size_t nz    = 1;
	size_t ny    = nz * nx;
	zdouble zero = 0.0;
	//
	// compute y = g(x) case where x[0] == 0.0
	zvector x(nx), y(ny);
	x[0] = 0.0;
	x[1] = 0.0;
	g(x, y);
	//
	// check results
	ok  &= CppAD::NearEqual(y[0], zero, eps, eps);
	ok  &= CppAD::NearEqual(y[1], zero, eps, eps);
	//
	// compute y = g(x) case where g(x) = x[0] / x[1]
	x[0] = 2.0;
	x[1] = 3.0;
	g(x, y);
	//
	// check results
	ok  &= CppAD::NearEqual(y[0], 1.0/x[1], eps, eps);
	ok  &= CppAD::NearEqual(y[1], -x[0]/(x[1]*x[1]), eps, eps);
	//
	if( ! ok )
		return 1;
	return 0;
}
EOF
#
# Compile test
echo_eval g++ \
	-g \
	-std=c++11 \
	-I../.. \
	tst_cppad_cg.cpp -o tst_cppad_cg
#
if ! ./tst_cppad_cg
then
	file="$HOME/install/cppad_cg/build/tst_cppad_cg.cpp"
	echo "install_cppad_cg.sh: Error"
	exit 1
fi
#
echo 'cppad_cg.sh: OK'
exit 0
